Wavelength conversion member and light emitting device

Abstract

A wavelength conversion member includes a support and a wavelength conversion layer including a first phosphor having a composition represented by Formula (1) and having an emission peak wavelength in a range from 550 nm to 620 nm, and a second phosphor having a different emission peak wavelength and/or a full width at half maximum from the first phosphor. An amount of the first phosphor in the wavelength conversion layer is in a range from 20 mass % to 80 mass % relative to a total amount of the phosphors In Formula (1), M 1 represents at least one of rare earth elements other than La and Ce, a total molar content percentage of Y, Gd, and Lu in M 1 is 90% or more, and p, q, r, and s satisfy 2.7≤(p+q+r)≤3.3, 0≤r≤1.2, 10≤s≤12, and 0<q≤1.2. La p Ce q M 1 r Si 6 N s   (1)

What is claimed is: 
     
       1. A wavelength conversion member comprising a support and a wavelength conversion layer, the wavelength conversion layer being disposed on the support and containing phosphors;
 the phosphors including:
 a first phosphor having a composition represented by Formula (1), and having an emission peak wavelength in a wavelength range from 550 nm to 620 nm; and 
 a second phosphor having a different emission peak wavelength and/or a full width at half maximum from the first phosphor; 
 wherein an amount of the first phosphor in the wavelength conversion layer is in a range from 20 mass % to 80 mass % relative to a total amount of the phosphors:
   La p Ce q M 1   r Si 6 N 8   (1)
 
 
 
 where in Formula (1), M 1  represents at least one selected from the group consisting of rare earth elements other than La and Ce, a total molar content percentage of Y, Gd, and Lu in M 1  is 90% or more, and p, q, r, and s satisfy: 2.7≤(p+q+r)≤3.3, 0≤r≤1.2, 10≤s≤12, and 0<q≤1.2. 
 
     
     
       2. The wavelength conversion member according to  claim 1 , wherein the amount of the first phosphor is in a range from 25 mass % to 75 mass % relative to the total amount of the phosphors. 
     
     
       3. The wavelength conversion member according to  claim 1 , wherein the second phosphor includes a phosphor having an emission peak wavelength in a wavelength range from 450 nm to 550 nm, and a full width at half maximum in a range from 90 nm to 130 nm. 
     
     
       4. The wavelength conversion member according to  claim 1 , wherein the second phosphor includes at least one selected from the group consisting of a phosphor having a composition represented by Formula (2) and a phosphor having a composition represented by Formula (3):
   Lu 3 (Ga,Al) 5 O 12 :Ce  (2),
 
   Y 3 (Ga,Al) 5 O 12 :Ce  (3).
 
 
     
     
       5. The wavelength conversion member according to  claim 4 , wherein
 the second phosphor includes the phosphor having the composition represented by Formula (2) and the phosphor having the composition represented by Formula (3), and 
 an amount of the second phosphors is in a range from 20 mass % to less than 80 mass % relative to the total amount of the phosphors. 
 
     
     
       6. The wavelength conversion member according to  claim 4 , wherein the amount of the second phosphors is in a range from 25 mass % to 75 mass % relative to the total amount of the phosphors. 
     
     
       7. The wavelength conversion member according to  claim 1 , wherein, in Formula (1), a molar content percentage of Y in M 1  is 90% or more. 
     
     
       8. A light emitting device comprising:
 the wavelength conversion member according to  claim 1 ; and 
 a light emitting element having an emission peak wavelength in a wavelength range from 350 nm to 500 nm. 
 
     
     
       9. The light emitting device according to  claim 8 , wherein the light emitting element is a laser diode.